Reaction process of {alpha} {yields} {gamma} massive transformation in Ti-rich TiAl alloy
- National Research Inst. for Metals, Ibaraki (Japan)
- Tokyo Inst. of Technology (Japan). Dept. of Metallurgical Engineering
Reaction sequence of the massive transformation from the high-temperature {alpha}-Ti phase to the {gamma}-TiAl phase ({gamma}{sub m}) in a Ti-48at.% Al alloy has been examined in terms of optical and transmission electron microscopes. Both transformed and untransformed regions were macroscopically observed in the sample quenched from the high-temperature {alpha} phase field, when the sample was held there for a extended period of time prior to quenching. The transformed region consists of randomly oriented fine {gamma} single phase grains, in which many thermal anti-phase domains (TAPDs), together with a number of stacking faults were observed. In contrast, the untransformed region comprises extremely fine lamellae of the {gamma} and {alpha}{sub 2}-Ti{sub 3}Al phases, and the {gamma} plates were found to run through the TAPDs caused by {alpha} {yields} {alpha}{sub 2} ordering. Subsequent aging at 1,273 K causes the microstructure change in the untransformed region from {alpha}{sub 2}/{gamma} lamellae to {gamma}/{gamma} lamellae spontaneously and expands the {gamma}{sub m} region. These observations suggest that the {alpha} {yields} {gamma}{sub m} transformation proceeds through formation of fine {gamma} plates.
- OSTI ID:
- 78318
- Report Number(s):
- CONF-941144-; ISBN 1-55899-265-0; TRN: IM9531%%371
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 28 Nov - 9 Dec 1994; Other Information: PBD: 1995; Related Information: Is Part Of High-temperature ordered intermetallic alloys VI: Part 1. Materials Research Society symposium proceedings Volume 364; Horton, J. [ed.] [Oak Ridge National Lab., Oak Ridge, TN (United States)]; Baker, I. [ed.] [Dartmouth College, Hanover, NH (United States)]; Hanada, Shuji [ed.] [Tohoku Univ., Sendai (Japan)]; Noebe, R.D. [ed.] [NASA Lewis Research Center, Cleveland, OH (United States)]; Schwartz, D.S. [ed.] [McDonnell Douglas Aerospace, St. Louis, MO (United States)]; PB: 713 p.
- Country of Publication:
- United States
- Language:
- English
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